- char shared[ECDH_SHARED_SIZE];
-
- if(!ecdh_compute_shared(&c->ecdh, key, shared))
- return false;
-
- /* Update our crypto end */
-
- if(!cipher_open_by_name(&c->incipher, "aes-256-ofb"))
- return false;
- if(!digest_open_by_name(&c->indigest, "sha512", -1))
- return false;
- if(!cipher_open_by_name(&c->outcipher, "aes-256-ofb"))
- return false;
- if(!digest_open_by_name(&c->outdigest, "sha512", -1))
- return false;
-
- size_t mykeylen = cipher_keylength(&c->incipher);
- size_t hiskeylen = cipher_keylength(&c->outcipher);
-
- char *mykey;
- char *hiskey;
- char *seed;
-
- if(strcmp(myself->name, c->name) < 0) {
- mykey = key;
- hiskey = key + mykeylen * 2;
- xasprintf(&seed, "tinc TCP key expansion %s %s", myself->name, c->name);
- } else {
- mykey = key + hiskeylen * 2;
- hiskey = key;
- xasprintf(&seed, "tinc TCP key expansion %s %s", c->name, myself->name);
- }
-
- if(!prf(shared, ECDH_SHARED_SIZE, seed, strlen(seed), key, hiskeylen * 2 + mykeylen * 2))
- return false;